Grinding control unit of a tool bit grinder

A grinding control unit installed in a tool bit grinder and adapted to control the feeding of a bit relative to a grinding wheel of a grinding unit of the tool bit grinder, the grinding control unit comprising:

• a U-shaped support, said U-shaped support comprising a round axle suspended between two upright side walls thereof, and a coupling block turned about and moved axially along said round axle, said coupling block having one end pivoted to said round axle and an opposite end terminating in a receptacle portion;
• a chuck mounted in said receptacle portion of said coupling block, said chuck having a plurality of pawls disposed at a front end thereof and adapted to hold down a bit for grinding by the grinding wheel of the grinding unit of the tool bit grinder, and a gradation wheel at a rear end thereof;
• a swinging control mechanism adapted for enabling said chuck to be turned with said coupling block about said round axle, said swinging control mechanism comprising a roller mounted on one upright side wall of said U-shaped support, and a cam wheel mounted on said chuck to guide movement of said chuck relative to said round axle, said cam wheel comprising a radially extended peripheral flange pressed on said roller;
• a feeder, said feeder comprising a flange formed integral with and axially extended from one side of said cam wheel and aimed at the receptacle portion of said coupling block, the flange of said feeder having two double-beveled protruding portions spaced at 180°, a pulley mounted outside the receptacle portion of said coupling block and disposed in contact with the flange of said feeder.